I think the NOC network operation centre are getting you to use ping correctly and iiNet.net.au is ping-able. They’re diagnosing packet loss. Run in cmd ping -n 200 52.64.91.12 and copy packet loss after it does the 200 ping tests. There’s an Australian standard if packet loss is over a certain percentage they need to arrange a house call tech appointment and he’ll also check your connection outside of your house to the pit. Also do a tracert google.com and make sure your internal network isn’t to blame and you reach the next hop outside your network. Remember some hops will not respond as they block it but internal network ie 192.168.x.x should and the one after that. Have a nice day and hope you get this sorted
Dog shit network, call the landlord out on it. Tell him you’re fed up and your lease includes internet, not a half working internet. If knowledgeable offer to do the installation yourself or demand a qualified technician. I’ve been in your situation and landlords think they can get away with leaky roofs and broken water pipes